U.S. patent application number 15/037111 was filed with the patent office on 2016-10-13 for ultrasonic treatment device.
This patent application is currently assigned to HITACHI, LTD.. The applicant listed for this patent is HITACHI, LTD., TOHOKU UNIVERSITY. Invention is credited to Kazunori ITANI, Hiroshi KANAI, Yoshinori SEKI, Hiroaki SHIMOKAWA.
Application Number | 20160296767 15/037111 |
Document ID | / |
Family ID | 53057498 |
Filed Date | 2016-10-13 |
United States Patent
Application |
20160296767 |
Kind Code |
A1 |
SEKI; Yoshinori ; et
al. |
October 13, 2016 |
ULTRASONIC TREATMENT DEVICE
Abstract
A probe (10) transmits and receives diagnostic ultrasound and
therapeutic ultrasound. A transmission unit (12) forms a
transmission beam of the therapeutic ultrasound having a higher
wave number than the diagnostic ultrasound and scans the
transmission beam of the therapeutic ultrasound in a therapeutic
region set inside a diagnostic region by controlling the probe
(10). Since the therapeutic ultrasound having a higher wave number
than the diagnostic ultrasound is used, the therapeutic effect is
higher than when using a therapeutic ultrasound having a similar
wave number to the diagnostic ultrasound, and since the
transmission beam of the therapeutic ultrasound is scanned in the
therapeutic region, the therapeutic effect is higher than when the
transmission beam of the therapeutic ultrasound is not scanned.
Inventors: |
SEKI; Yoshinori; (Tokyo,
JP) ; ITANI; Kazunori; (Tokyo, JP) ;
SHIMOKAWA; Hiroaki; (Miyagi, JP) ; KANAI;
Hiroshi; (Miyagi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HITACHI, LTD.
TOHOKU UNIVERSITY |
Tokyo
Miyagi |
|
JP
JP |
|
|
Assignee: |
HITACHI, LTD.
Tokyo
JP
TOHOKU UNIVERSITY
Miyagi
JP
|
Family ID: |
53057498 |
Appl. No.: |
15/037111 |
Filed: |
November 17, 2014 |
PCT Filed: |
November 17, 2014 |
PCT NO: |
PCT/JP2014/080365 |
371 Date: |
May 17, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 8/5207 20130101;
A61N 2007/0052 20130101; A61N 2007/0082 20130101; A61N 7/00
20130101; A61B 2017/22005 20130101; A61B 8/0883 20130101; A61B 8/54
20130101; A61N 7/02 20130101; A61N 2007/0073 20130101; A61N
2007/0004 20130101 |
International
Class: |
A61N 7/00 20060101
A61N007/00; A61B 8/00 20060101 A61B008/00; A61B 8/08 20060101
A61B008/08 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 18, 2013 |
JP |
2013-237707 |
Claims
1. An ultrasonic treatment device comprising: a probe that
transmits and receives ultrasound; a transmission unit that scans a
transmission beam of diagnostic ultrasound in a diagnostic region
by controlling the probe; a receiving unit that obtains a received
signal of diagnostic ultrasound along a receiving beam
corresponding to the transmission beam of diagnostic ultrasound;
and an image-forming unit that forms an ultrasound image of the
diagnostic region based on the received signal of diagnostic
ultrasound, wherein the transmission unit forms a transmission beam
of therapeutic ultrasound by controlling the probe, and scans the
transmission beam of therapeutic ultrasound within a treatment
region which is set to be in the diagnostic region.
2. The ultrasonic treatment device according to claim 1, wherein
the transmission unit forms a transmission beam of therapeutic
ultrasound having a larger wavenumber than that of diagnostic
ultrasound, and scans the transmission beam of therapeutic
ultrasound within the treatment region which is set to be in the
diagnostic region.
3. The ultrasonic treatment device according to claim 1, wherein
the transmission unit controls the probe so as to transmit
therapeutic ultrasound having a wavenumber of 6 to 64 cycles.
4. The ultrasonic treatment device according to claim 2, wherein
the transmission unit controls the probe so as to transmit
therapeutic ultrasound having a wavenumber of 32 cycles.
5. The ultrasonic treatment device according to claim 3, wherein
the transmission unit scans the transmission beam of therapeutic
ultrasound in the treatment region including an ischemic
tissue.
6. The ultrasonic treatment device according to claim 4, wherein
the transmission unit scans the transmission beam of therapeutic
ultrasound in the treatment region including an ischemic
tissue.
7. The ultrasonic treatment device according to claim 5, wherein
the transmission unit sets a focal point of the transmission beam
of therapeutic ultrasound at the depth of the ischemic tissue.
8. The ultrasonic treatment device according to claim 6, wherein
the transmission unit sets a focal point of the transmission beam
of therapeutic ultrasound at the depth of the ischemic tissue.
9. The ultrasonic treatment device according to claim 1, wherein a
diagnostic mode that uses diagnostic ultrasound and a treatment
mode that uses therapeutic ultrasound are provided; in the
treatment mode, the transmission unit scans the transmission beam
of therapeutic ultrasound within the treatment region; the
receiving unit obtains a received signal of therapeutic ultrasound
from the inside of the treatment region along the receiving beam
corresponding to the transmission beam of therapeutic ultrasound;
and the image-forming unit forms an ultrasonic image of the
treatment region based on the received signal of therapeutic
ultrasound.
10. The ultrasonic treatment device according to claim 9, wherein
the transmission unit scans, in the treatment mode, the
transmission beam of therapeutic ultrasound within the treatment
region including the ischemic tissue.
11. The ultrasonic treatment device according to claim 10, wherein
the transmission unit sets, in the treatment mode, the focal point
of the transmission beam of therapeutic ultrasound at the depth of
the ischemic tissue.
12. The ultrasonic treatment device according to claim 1, wherein a
diagnostic mode that uses diagnostic ultrasound and a treatment
mode that uses therapeutic ultrasound are provided; in the
treatment mode, the transmission unit scans the transmission beam
of therapeutic ultrasound within the treatment region so as to
change radiation pressure of therapeutic ultrasound periodically,
and causes a treatment site to swing using changing radiation
pressure.
13. The ultrasonic treatment device according to claim 12, wherein
the transmission unit scans, in the treatment mode, the
transmission beam of therapeutic ultrasound within the treatment
region so as to change radiation pressure of therapeutic ultrasound
periodically, and causes the ischemic tissue which is the treatment
site to swing using changing radiation pressure.
14. The ultrasonic treatment device according to claim 1, wherein
the therapeutic ultrasound is transmitted at the repetition
frequency according to the size of a tissue to be treated and the
speed of a transverse wave of the tissue.
15. The ultrasonic treatment device according to claim 3, wherein
the therapeutic ultrasound is transmitted at the repetition
frequency according to the size of a tissue to be treated and the
speed of a transverse wave of the tissue.
16. The ultrasonic treatment device according to claim 5, wherein
the therapeutic ultrasound is transmitted at the repetition
frequency according to the size of a tissue to be treated and the
speed of a transverse wave of the tissue.
17. The ultrasonic treatment device according to claim 7, wherein
the therapeutic ultrasound is transmitted at the repetition
frequency according to the size of a tissue to be treated and the
speed of a transverse wave of the tissue.
18. The ultrasonic treatment device according to claim 9, wherein
the therapeutic ultrasound is transmitted at the repetition
frequency according to the size of a tissue to be treated and the
speed of a transverse wave of the tissue.
19. The ultrasonic treatment device according to claim 12, wherein
the therapeutic ultrasound is transmitted at the repetition
frequency according to the size of a tissue to be treated and the
speed of a transverse wave of the tissue.
20. The ultrasonic treatment device according to claim 13, wherein
the therapeutic ultrasound is transmitted at the repetition
frequency according to the size of a tissue to be treated and the
speed of a transverse wave of the tissue.
Description
TECHNICAL FIELD
[0001] The present invention relates to an ultrasonic treatment
device.
BACKGROUND
[0002] In treatment of an ischemic tissue, such as, for example,
treatment of ischemic heart disease, invasive treatments by
surgical operations have been carried out so far. This treatment
method is highly invasive to and imposes a significant burden on
the patient.
[0003] Accordingly, in recent years, a method of treating ischemic
tissues using shock waves has been developed. It is a method of
treating, for example, a cardiac muscle tissue which has been
damaged due to stenosis or occlusion of a part of the coronary
arteries of the heart, by applying weak shock waves to the tissue.
A known therapeutic effect is that when an ischemic tissue is
irradiated with shock waves, regeneration of new blood vessels is
promoted at that irradiated site. This treatment method is
non-invasive and places only a small burden on the patient. As an
example of a device that implements such a treatment method, for
example, a device disclosed in Patent Document 1 is known. This
device is an application of a calculus-crushing device, and applies
to the affected part shock waves with a weaker output than the
calculus-crushing device.
[0004] Because the device of the type disclosed in Patent Document
1 cannot obtain an in-vivo image using a shock wave irradiation
head, an ultrasonic diagnostic device for identifying an
irradiation site, etc. must be provided separately. However,
because a probe of the ultrasonic diagnostic device cannot be
placed in the same position as the shock wave irradiation head, a
diagnostic image of the ultrasonic diagnostic device is obtained
from a viewpoint and a gaze direction different from that of the
shock wave irradiation head.
[0005] In addition, because the shock wave irradiation head is
relatively large, for example, in the treatment of the heart, shock
waves are applied not only to the cardiac muscle to be treated but
also to other tissues, such as a rib and a pulmonary tissue. In
this case, because the rib and the pulmonary tissue have acoustic
impedance values that are very different from those of living soft
tissues, shock waves cause reflection and scattering at a boundary
with the living soft tissues, and shock waves reaching the cardiac
muscle or the like which is a treatment object are reduced, while
shock waves reaching the tissues other than the treatment object
are increased.
[0006] In view of such circumstances, the applicant of the present
application proposes, in Patent Document 2, an ultrasonic treatment
device that minimizes irradiation of ultrasound to sites other than
a treatment site.
CITATION LIST
Patent Literature
[0007] Patent Document 1: JP 3058645 B
[0008] Patent Document 2: JP 2011-15732 A
SUMMARY
Technical Problem
[0009] In view of the above-described background art, the inventors
of the present application have continued research and development
for further improvement of the ultrasonic treatment device.
Solution To Problem
[0010] The present invention has been achieved in the process of
that research and development, and its purpose is to provide an
ultrasonic treatment device having higher therapeutic effect than
that of the prior art.
[0011] A preferable ultrasonic treatment device that fulfills the
above-described purpose has a probe that transmits and receives
ultrasound, a transmission unit that scans a transmission beam of
diagnostic ultrasound in a diagnostic region by controlling the
probe, a receiving unit that obtains a received signal of
diagnostic ultrasound along a receiving beam corresponding to the
transmission beam of diagnostic ultrasound, and an image-forming
unit that forms an ultrasound image of the diagnostic region based
on the received signal of diagnostic ultrasound, and in this
device, the transmission unit forms a transmission beam of
therapeutic ultrasound by controlling the probe, and scans the
transmission beam of therapeutic ultrasound within a treatment
region which is set to be in the diagnostic region.
[0012] In the above device, diagnostic ultrasound has a wavenumber
and an irradiation intensity that are a similar level to ultrasound
used in, for example, diagnosis in a conventional general
ultrasonic diagnostic device, and diagnostic ultrasound is
transmitted and received, for example, using a vibration element of
a conventional general ultrasonic diagnostic device. In contrast,
therapeutic ultrasound is desirably has a larger wavenumber than
diagnostic ultrasound. Therapeutic ultrasound may have an
irradiation intensity that is a similar level to diagnostic
ultrasound, and therapeutic ultrasound can be transmitted and
received using a vibration element for transmitting and receiving
diagnostic ultrasound. As a matter of course, a vibration element
for transmitting and receiving diagnostic ultrasound and a
vibration element for transmitting and receiving therapeutic
ultrasound may be provided separately.
[0013] With the above device, because therapeutic ultrasound having
a larger wavenumber than that of diagnostic ultrasound is used, the
therapeutic effect is enhanced as compared to the case where
therapeutic ultrasound having a wavenumber that is of a similar
level to diagnostic ultrasound is used. For example, if the
wavenumber diagnostic ultrasound is one or two cycles or so, the
wavenumber of therapeutic ultrasound is set to be more than three
cycles. In order to further enhance the therapeutic effect, the
wavenumber of therapeutic ultrasound is desirable to be more than,
for example, six cycles, and is selected from 16 cycles, 32 cycles,
48 cycles, and 64 cycles, for example. According to the
experimental results, the highest therapeutic effect is expected to
be obtained from 32 cycles, and therefore, it is particularly
desirable to set the wavenumber of therapeutic ultrasound to 32
cycles. As a matter of course, as the high therapeutic effect is
expected from wavenumbers that are a similar level to 32 cycles,
the wavenumber of therapeutic ultrasound is not strictly limited to
32 cycles, and it may be set to a wavenumber that is a similar
level to 32 cycles. Wavenumbers that are of a similar level to 32
cycles include, for example, 16 to 48 cycles, and, desirably, are
24 to 40 cycles, but are not limited to these examples.
[0014] In addition, with the above device, because a transmission
beam of therapeutic ultrasound is scanned within the treatment
region, the therapeutic effect is enhanced as compared to the case
where the transmission beam of therapeutic ultrasound is not
scanned. Modes of scanning the transmission beam of therapeutic
ultrasound include not only continuous scanning by shifting an
angle or a position of the transmission beam for each line but also
discrete scanning by changing an angle or a position of the
transmission beam over a plurality of lines regularly or
irregularly. According to the experimental results, although there
is improvement in the treatment site (e.g. ischemic tissue) when it
is irradiated with therapeutic ultrasound having a larger
wavenumber than diagnostic ultrasound, a normal site (e.g. normal
tissue) is not affected significantly. Therefore, even if the
treatment sites and the normal sites are mixed in the treatment
region,therapeutic ultrasound is transmitted over e entire area of
the treatment region while suppressing the effect on the normal
site, thereby treating the treatment sites over the entire region
of the treatment region. In other words, by scanning the
transmission beam of therapeutic ultrasound within the treatment
region, wide area treatment is enabled, and the therapeutic effect
of the entire treatment region is enhanced.
[0015] In a desirable specific example, for example, the
transmission unit control probe so as to transmit therapeutic
ultrasound having a wavenumber of 32 cycles.
[0016] In a desirable specific example, the ultrasonic treatment
device has a diagnostic mode that uses diagnostic ultrasound and a
treatment mode that uses therapeutic ultrasound. In the treatment
mode, the transmission unit scans the transmission beam of
therapeutic ultrasound within the treatment region; the receiving
unit obtains a received signal of therapeutic ultrasound from the
inside of the treatment region along the receiving beam
corresponding to the transmission beam of therapeutic ultrasound;
and the image-forming unit forms an ultrasonic image of the
treatment region based on the received signal of therapeutic
ultrasound.
[0017] In a desirable specific example, the ultrasonic treatment
device has a diagnostic mode that uses diagnostic ultrasound and a
treatment mode that uses therapeutic ultrasound. In the treatment
mode, the transmission unit scans the transmission beam of
therapeutic ultrasound within the treatment region an as to change
radiation pressure of therapeutic ultrasound periodically, and
causes a treatment site to swing using changing radiation
pressure.
Advantageous Effects of Invention
[0018] The present invention provides an ultrasonic treatment
device having higher therapeutic effect than in the prior art. For
example, according to a preferable embodiment of the present
invention, because therapeutic ultrasound having a larger
wavenumber than that of diagnostic ultrasound is used, the
therapeutic effect is enhanced as compared to the case where
therapeutic ultrasound having a wavenumber that is of a similar
level to diagnostic ultrasound is used. In addition, for example,
according to a preferable embodiment of the present invention,
because the transmission beam of therapeutic ultrasound is scanned
within the treatment region, the therapeutic effect is enhanced as
compared to the case where the transmission beam of therapeutic
ultrasound is not scanned.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 shows a diagram showing the entire configuration of a
preferable ultrasonic treatment device in an embodiment of the
present invention.
[0020] FIG. 2 shows a diagram showing specific examples of
diagnostic ultrasound and therapeutic ultrasound.
[0021] FIG. 3 shows a diagram showing experimental results relating
to expression of vascular endothelial growth factors.
[0022] FIG. 4 shows a diagram showing experimental results relating
to impact of therapeutic ultrasound on tissues.
[0023] FIG. 5 shows a diagram showing experimental results relating
to the capillary density.
[0024] FIG. 6 shows a diagram showing a specific example of
scanning of therapeutic ultrasound.
[0025] FIG. 7 shows a flowchart showing an operation example of the
ultrasonic treatment device of FIG. 1.
DESCRIPTION OF EMBODIMENTS
[0026] FIG. 1 shows the entire configuration diagram of a
preferable ultrasonic treatment device 100 in implementation of the
present invention. The ultrasonic treatment device 100 is suitable
for treatment of ischemic tissues, for example, and an example of a
preferable treatment object is the heart. As a matter of course,
treatment objects of the ultrasonic treatment device 100 are not
limited to the heart, and for example, vessels and organs other
than the heart may also be treatment objects. The ultrasonic
treatment device 100 uses diagnostic ultrasound and therapeutic
ultrasound.
[0027] A probe 10 has a plurality of vibration elements (not shown)
for transmitting and receiving diagnostic ultrasound and
therapeutic ultrasound. The plurality of vibration elements may be
in any element arrangement according to, such as, for example, a
convex scan type, a sector scan type, and a linear scan type, or
any element arrangement for a two-dimensional image (tomographic
image) and for a three-dimensional image. Although it is desirable
that each of the plurality of vibration elements provided in the
probe 10 can transmit and receive both diagnostic ultrasound and
therapeutic ultrasound, vibration elements for transmitting and
receiving diagnostic ultrasound and vibration elements for
transmitting and receiving therapeutic ultrasound may be provided
separately.
[0028] A transmission unit 12 outputs transmission signals to the
plurality of vibration elements provided in the probe 10, to
thereby control the probe 10. The transmission unit 12 scans the
transmission beam of diagnostic ultrasound within a diagnostic
region by controlling the probe 10. The transmission unit 12 also
scans a transmission beam of therapeutic ultrasound within a
treatment region by controlling the probe 10. In other words, the
transmission unit 12 has the function as a transmission beam
former. Specific scanning processing by the transmission unit 12
will be described in detail later.
[0029] A receiving unit 14 forms a receiving beam, for example, by
performing phasing addition processing on the plurality of wave
receiving signals obtained from the plurality of vibration elements
provided in the probe 10, thereby obtaining received signals along
the receiving beam. In other words, the receiving unit 14 has the
function as a receiving beam former. The receiving unit 14 forms a
receiving beam corresponding to the transmission beam of diagnostic
ultrasound, to thereby obtain received signals of diagnostic
ultrasound from the inside of the diagnostic region. The receiving
unit 14 also forms a receiving beam corresponding to the
transmission beam of therapeutic ultrasound, to thereby obtain
received signals of therapeutic ultrasound from the inside of the
treatment region.
[0030] An image-forming unit 20 forms an ultrasonic image of the
diagnostic region based on the received signals of diagnostic
ultrasound. The image-forming unit 20 also forms an ultrasonic
image of the treatment region based on the received signals of
therapeutic ultrasound. A preferable specific example of an
ultrasonic image is a B-mode image obtained by known B-mode imaging
processing. The image-forming unit 20 may also form, as the
ultrasonic image, a three-dimensional ultrasonic image or a color
Doppler image, for example. The ultrasonic image formed in the
image-forming unit 20 is displayed on a display unit 30.
[0031] A control unit 40 controls the inside the ultrasonic
treatment device 100 intensively. An operation device 50 is a
device that receives the user's operation, and an instruction
received by the operation device 50 from the user is transmitted to
the control unit 40 and is reflected on the control of the inside
of the ultrasonic treatment device 100.
[0032] Each of the transmission unit 12, the receiving unit 14, and
the image-forming unit 20 is implemented using hardware, such as,
for example, a processor and an electronic circuit. In addition, a
preferable specific example of the display unit 30 is, for example,
a liquid crystal display, etc. Further, the operation device 50 is
composed of at least sonic of, for example, a mouse, track ball,
keyboard, touch panel, other switches, etc. Still further, the
control unit 40 is composed of, for example, hardware such as a CPU
having a calculation function, and when the hardware works in
cooperation with software (program) that defines operation of the
hardware, the functions of the control unit 40 are implemented.
[0033] The entire configuration of the ultrasonic treatment device
100 is as described above. Next, the functions and the like that
are implemented by the ultrasonic treatment device 100 will be
described in detail. In the following description, the components
(parts) that are shown in FIG. 1 use the same reference numerals as
in FIG. 1.
[0034] FIG. 2 shows a diagram showing specific examples of
diagnostic ultrasound and therapeutic ultrasound. FIG. 2 shows
waveforms of diagnostic ultrasound and therapeutic ultrasound
transmitted in the ultrasonic treatment device 100 in FIG. 1.
[0035] Diagnostic ultrasound has the wavenumber and the irradiation
intensity that area similar level to those of ultrasound used in
diagnosis, for example, by conventionally-known general ultrasonic
diagnostic devices. Ultrasound used in diagnosis by a general
ultrasonic diagnostic device has, typically, one or two cycles or
so. Therefore, in the ultrasonic treatment device 100 in FIG. 1,
the wavenumber of diagnostic ultrasound is, for example, one or two
or so. FIG. 2<A> shows, as a specific example of diagnostic
ultrasound, a waveform having a wavenumber of one (one cycle). As
diagnostic ultrasound, for example, waveforms having two to six
cycles or so may also be used.
[0036] Meanwhile, therapeutic ultrasound has long bursting waves
having larger wavenumbers than diagnostic ultrasound. It is
desirable that the wavenumber of therapeutic ultrasound is, for
example, greater than six cycles, and more specifically, it is
selected from, for example, 16 cycles, 32 cycles, 48 cycles, and 64
cycles. FIG. 2<B> shows, as a specific example of therapeutic
ultrasound, a waveform having a wavenumber of 16 (16 cycles); FIG.
2<C> shows, as a specific example of therapeutic ultrasound,
a waveform having wavenumber of 32 (32 cycles); and FIG. 2<D>
shows, as a specific example of therapeutic ultrasound, a waveform
having wavenumber of 64 (64 cycles).
[0037] FIG. 3 shows a diagram showing experimental results relating
to expression of vascular endothelial growth factors. FIG. 3 shows
expression of vascular endothelial growth factors (VEGF) (vertical
axis) when wavenumbers of therapeutic ultrasound are set to be 1 (1
cycle), 16 (16 cycles), 32 (32 cycles), 48 (48 cycles), and 64 (64
cycles), and the expression is highest in the case of 32 cycles. In
other words, according to these experimental results, the
therapeutic effect is highest in the ischemic tissue when
therapeutic ultrasound has a wavenumber of 32 cycles. Therefore, in
the ultrasonic treatment device 100 in FIG. 1, therapeutic
ultrasound having a wavenumber of, for example, 32 cycles is
used.
[0038] FIG. 4 shows a diagram showing experimental results relating
to impact of therapeutic ultrasound on tissues. FIG. 4<A>
shows experimental results relating to expression of vascular
endothelial growth factors (VEGF); FIG. 4<B> shows
experimental results relating to expression of endothelial nitric
oxide synthase (eNOS); and FIG. 4<C> shows experimental
results relating to expression of basic fibroblast growth factors
(bFGF). FIGS. 4<A> to <C> show expression amounts of
the factors obtained when therapeutic ultrasound is transmitted to
both of the ischemic tissue and a normal tissue.
[0039] As shown in FIG. 4, although, in all the factors from
<A> to <C>, the expression is promoted in the ischemic
tissue by transmitting therapeutic ultrasound, while expression is
suppressed in the normal tissue. In other words, by using
therapeutic ultrasound, the therapeutic effect on the ischemic
tissue appears, while the impact on the normal tissue is
suppressed.
[0040] FIG. 5 shows a diagram showing experimental results relating
to capillary density. FIG. 5 shows the capillary density obtained
when therapeutic ultrasound is transmitted to both of the ischemic
tissue and the normal tissue. As shown in FIG. 5, by transmitting
therapeutic ultrasound, the capillary density is increased in the
ischemic tissue, while the increase in the capillary density is
suppressed in the normal tissue. In other words, by using
therapeutic ultrasound, the capillary density is enhanced only in
the ischemic site.
[0041] Therefore, even if the treatment sites (ischemic tissue) and
the normal sites (normal tissue) are mixed in the treatment region,
the ultrasonic treatment device 100 in FIG. 1 treats the treatment
sites over the entire area of the treatment region, suppressing the
effect on the normal sites by scanning the transmission beam of
therapeutic ultrasound over the entire area of the treatment
region.
[0042] FIG. 6 shows a diagram showing a specific example of
scanning of therapeutic ultrasound. FIG. 6 shows a specific example
of the case in which the ischemic tissue in the cardiac muscle of
the heart is treated, and FIG. 6 shows a display image 32 that is
displayed on the display unit 3. The display image 32 includes an
ultrasonic image of the treatment region including the heart; that
is, a B-mode image of a cardiac short axis (short-axis image).
[0043] The B-mode image of the cardiac short axis is formed by
known B-mode image forming processing via diagnostic ultrasound.
More specifically, the transmission unit 12 scans the transmission
beam of diagnostic ultrasound within the diagnostic region, and the
receiving unit 14 collects received signals from the diagnostic
region along a receiving beam corresponding to the transmission
beam. The image-forming unit 20 forms a B-mode image of the
diagnostic region based on the received signals.
[0044] Once the B-mode image of the diagnostic region is formed,
the treatment region is set so as to include the ischemic tissue of
the cardiac muscle, which is the treatment site. For example, as
shown in FIG. 6, an angle .theta.1 of a right side boundary line
and an angle .theta.2 of a left side boundary line are set within
the diagnostic region, and the region between the set right side
boundary line and the left side boundary line is the treatment
region. The user (person who provides treatment, such as a medical
doctor) of the ultrasonic treatment device 100 operates the
operation device 50 such as a track ball, while looking at the
display image 32 showing the cardiac short axis image, to thereby
adjust the angle .theta.1 of the right side boundary line and the
angle .theta.2 of the left side boundary line and set the treatment
region to be within the diagnostic region.
[0045] Once the treatment region is set, the transmission unit 12
scans a transmission beam of therapeutic ultrasound within the
treatment region, and conducts treatment of the ischemic tissue.
The transmission unit 12 scans the transmission beam of therapeutic
ultrasound, for example, as shown in FIG. 6, in the order from line
1 corresponding to the right side boundary line, lines 2, 3, 4 . .
. until line n corresponding to the left side boundary line. The
transmission unit 12 may also perform scanning so as to shift the
lines of transmission beam over a plurality of lines regularly or
irregularly, in place of performing scanning so as to shift the
lines of the transmission beam one by one.
[0046] Desirably, a focal point of the transmission beam of
therapeutic ultrasound (focus depth) is set at the depth where the
ischemic tissue exists. For example, the user operates the
operation device 50, while looking at the display image 32, thereby
setting the focus depth of therapeutic ultrasound. A treatment
range of the treatment region (pulse repetition period of
therapeutic ultrasound) may also be the same as a diagnostic range
of the diagnostic region (pulse repetition period of diagnostic
ultrasound), or the treatment range of the treatment region may
also be adjusted in accordance with the focus depth of therapeutic
ultrasound.
[0047] It is also known that tissue is displaced by radiation force
of ultrasound which is generated when ultrasound is transmitted to
the tissue. Therefore, the transmission unit 12 scans a
transmission beam of therapeutic ultrasound within the treatment
region so as to change radiation pressure of therapeutic ultrasound
periodically, and causes the treatment site to swing using changing
radiation pressure. The therapeutic effect is further increased by
transmitting therapeutic ultrasound while causing the treatment
site to swing.
[0048] The range in which the tissue vibrates is determined by the
repetition frequency of ultrasound and the speed of a transverse
wave. Because the speed of the transverse wave in vivo is about 1
to 10 m/sec, for example, if the speed of the transverse wave in
the tissue is 1 m/sec, and if ultrasound is transmitted repeatedly
at the period of 100 Hz, the range having a length of 10 mm near
the focal point of ultrasound is vibrated more effectively. By
determining the repetition frequency of therapeutic ultrasound
according to the size of the tissue to be treated and the speed of
the transverse wave, the therapeutic effect additionally including
the effect of mechanical vibration by the radiation force can be
expected.
[0049] FIG. 6 shows a specific example of a transmission sequence
of therapeutic ultrasound that is preferable for vibration by
radiation force. In the specific example shown in FIG. 6, the
transmission beams of therapeutic ultrasound are scanned in the
order from lines 1, 2, 3, 4 . . . until line n. Assuming that the
pulse repetition frequency (PRF) between adjacent beams is 10 kHz,
and that the number of beams n is 100, the period in which
therapeutic ultrasound is applied to the same tissue position
becomes 100 Hz, and the tissue position can be vibrated
effectively. The treatment site may also be vibrated by ultrasound
for radiation which generates radiation force, in place of
therapeutic ultrasound.
[0050] FIG. 7 shows a flowchart showing a treatment example by the
ultrasonic treatment device of FIG. 1. First, a diagnostic mode
using diagnostic ultrasound is performed before a treatment mode
using therapeutic ultrasound. More specifically, transmission and
receiving of diagnostic ultrasound is started (S601), and an
ultrasonic image of the diagnostic region relating to a subject
including the treatment site is displayed (S602).
[0051] The user (person who provides treatment, such as a medical
doctor) of the ultrasonic treatment device 100 moves the probe 10
manually when necessary, looking at an ultrasonic image displayed
on the display unit 30 (e.g. the cardiac short axis image shown in
FIG. 6), to thereby search the treatment site in the subject
(S603). Once the treatment site has been searched, the user
operates the operation device 50 and sets the treatment region (by
way of example, the angle .theta.1 and the angle .theta.2 shown in
FIG. 6) so that the treatment site shown in the ultrasonic image is
included in the treatment region (S604). If the ultrasonic image is
a three-dimensional image, for example, a two-dimensional treatment
region (angle .theta.1 and angle .theta.2) may be set in any
two-dimensional plane, and a two-dimensional treatment region
(angle .theta.3 and angle .theta.4) may be set in a two-dimensional
plane intersecting with (for example, orthogonal to) the
two-dimensional plane, thereby setting a three-dimensional
stereoscopic treatment region based on these two-dimensional
treatment regions. As a matter of course, methods for setting the
three-dimensional treatment region are not limited to the above
specific example. The user further sets the focus depth relating to
the transmission beam of therapeutic ultrasound so that therapeutic
ultrasound is transmitted to the treatment site effectively, and
sets a treatment range of the treatment region to which therapeutic
ultrasound is transmitted (S605).
[0052] After setting for treatment is ended, the ultrasonic
treatment device 100 is switched from the diagnostic mode to the
treatment mode (S606), and transmission of therapeutic ultrasound
is started. A transmission beam of therapeutic ultrasound is
scanned within the treatment region (S607), and treatment is
conducted by therapeutic ultrasound. Desirably, the probe 10 is
fixed using, for example, a jig at any timing after search for the
treatment site (S603) is performed and before transmission of
therapeutic ultrasound is started (S607).
[0053] Moreover, while the transmission beam of therapeutic
ultrasound is scanned within the treatment region, and treatment is
conducted, the receiving unit 14 forms a receiving beam
corresponding to the transmission beam of therapeutic ultrasound
and obtains received signals of therapeutic ultrasound from the
inside of the treatment region. Then, the image forming unit 20
forms an ultrasound image (e.g. B-mode image) of the treatment
region based on the received signals of therapeutic ultrasound, and
the formed ultrasound image is displayed on the displayed unit 30
(S608). Thus, the user can confirm a treatment state from the
ultrasonic image of the treatment region. The user can confirm, for
example, whether or not therapeutic ultrasound is being transmitted
to the treatment region.
[0054] Thus, after treatment is performed on the treatment region,
which has been set in S604, for example, for about 20 minutes,
transmission of therapeutic ultrasound is ended (S609), and
treatment for the treatment region is ended. If there is a need to
set a plurality of treatment regions in the subject, the flowchart
in FIG. 7 is implemented for each treatment region, for
example.
[0055] Although the preferable embodiment of the present invention
has been described, the above-described embodiment is merely an
example in all respects, and should not be deemed to limit the
present invention. The present invention includes various
variations without departing from the spirit of the present
invention.
REFERENCE SIGNS LIST
[0056] 10 probe, 12 transmission unit, 14 receiving unit, 20
image-forming unit, 30 display unit, 40 control unit, 50 operation
device, 100 ultrasonic treatment device.
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